Field of the Invention
The invention relates to a touch system, and more particularly to a touch apparatus and a correction method thereof.
Description of Related Art
In recent years, touch electronic products have been very popular with consumers and have gradually become the mainstream in the market due to easy operation and highly intuitive mechanism. Currently, according to difference in structure and sensing manner, touch panels are mainly classified into resistive touch panels, capacitive touch panels, sound wave touch panels, optical touch panels, electromagnetic touch panels, etc. Among them, optical touch panels have advantages such as low cost and good accuracy, and thus has gained superiority in the competitive market. Today, they have also become the predominant choice for large-size touch screens.
An optical touch panel works as follows. A plurality of optical lenses are disposed at an edge of a screen, configured to capture an image of operation performed by a user's finger on the screen. Then, a position in a captured image where a shadow is cast by the finger that blocks light is analyzed, so as to obtain a relative angle between a touch point touched by the finger and the optical lenses. Finally, according to a known distance between the optical lenses, a system position corresponding to the touch point is calculated by a triangulation method. However, the optical touch panel has a problem in that a touch position and the system position may not match due to positional deviation of the optical lenses.